针线 (needle and thread) is also a metonym for women's domestic handiwork:
做针线 means 'to sew / do needlework'. The line
临行密密缝 (a mother sews tightly before her son's journey) from Meng Jiao's
《游子吟》 ('Song of the Wanderer') made the
针线 image a classical symbol of maternal love.
